Subject: RE: [mobile-ip] Mobile IPv6 - Issue 72 (Forwarding from previous CoA)

From: [email-masked]
Date: Fri, 13 Sep 2002 16:09:41 -0700

Since this feature is implemented as part of normal HA behavior and it has been there for ages, I would like to suggest to place it to the annex of the document rather than cut it out.

In some scenarios this would still be a useful deployment of Home Agents, especially if they have a group SA among themselves. This is a special case of course, and it is not able to provide the same seamless operation as Fast Handovers would.

Regards Hannu

-----Original Message-----
From: ext [email-masked] [mailto:[email-masked]]
Sent: 13 September, 2002 2:34 PM
To: [email-masked]
Subject: [mobile-ip] Mobile IPv6 - Issue 72 (Forwarding from previous
CoA)

Issue 72: Forwarding from Previous Care of Address
--------------------------------------------------

http://www.piuha.net/~jarkko/publications/mipv6/issues/issue72.txt

Section 11.6.6 of the Mobile IPv6 specification describes the ability
to forward packets from a previous CoA to the new CoA as a result of
the MN connecting to a new link.

Since the BU sent to an HA on the previous link requires the same
security as the BUs sent to the MNs Home Agent (on home link), this is
quite a difficult proposition from an implementation and deployment
perspective. So,

Recommendation:
---------------

The Mobile IP WG is currently working on fast handoffs for Mobile IPv6
which deals with the aspect of forwarding packets from the previous
CoA to the new CoA (draft-ietf-mobileip-fast-mipv6-04.txt).

Hence this entire feature can effectively be dropped out of the base
Mobile IPv6 specification and pursued independently as a separate
feature for IPv6 mobility. 
All text associated with the forwarding from previous CoA will be
deleted from the current specification.

If you have any concerns or views on why this feature should be a part
of the base specification, please post them to the list. 

-Basavaraj

---

From: "James Kempf" <[email-masked]>
Date: Mon, 16 Sep 2002 08:19:55 -0700

Hannu,

> Since this feature is implemented as part of normal HA behavior and it has
been there for ages, I would like to suggest to place it to the annex of the
document rather than cut it out.

The proposal isn't to drop it the feature, but to move it to a separate
document. The fast handover document already contains the basic functionallity,
so it is more logical to put it into that document.

> In some scenarios this would still be a useful deployment of Home Agents,
especially if they have a group SA among themselves. This is a special case of
course, and it is not able to provide the same seamless operation as Fast
Handovers would.

I'm not sure I understand your comment. This functionality has nothing to do
with the Home Agent, it has to do with the Access Router. Sometimes an Access
Router that provides this functionality is called an "on-link" Home Agent, is
that what you are talking about? If so, I don't understand your comment about an
SA. An SA among a group of such "on-link" Home Agents isn't equivalent to an SA
between the "on-link" Home Agents and the Mobile Node. Should such an SA exist,
the Mobile Node would have to verify it, and the pre-existence of such an SA
between an Access Router and a random Mobile Node is highly unlikely in the
first place. So the security aspects of providing this functionality are
currently undefined. Rather than delay the base spec any longer to define them,
why not consolidate the functionality to another spec which is trying to provide
that functionality, and deal with the security aspects at our leisure there?

            jak